code: def validation_step(self, batch, batch_idx):
      input_ids = batch["input_ids"]
      labels = batch["label"]
      loss, outputs = self(input_ids, labels)
      self.log("test_loss", loss)
      self.valid_f1(outputs, labels.int())
      self.log("valid_f1", self.valid_f1, on_step=True, on_epoch=True)
  
file_path: underthesea/examples/sentiment/train_gpt2.py
imports: import hydra
  import pytorch_lightning
  from omegaconf import DictConfig
  from torch.optim import SGD
  import torch.nn
  from torchmetrics import F1Score
  from transformers import AutoTokenizer, AutoModelWithLMHead
  from pytorch_lightning.loggers import WandbLogger
  from examples.sentiment.data import MultiLabelClassificationDatamodule
  from underthesea.datasets.uit_absa_hotel.uit_absa_hotel import UITABSAHotel
label_desc: Use image node_id 4 for calling the GPT2TextClassification obj's underlying member method code with example usage: obj.validation_step(batch, batch_idx) without return types